A mixed-pattern Terraforce® wall design allowed for the easy planting of a steeply inclined wall at the northeastern quadrant of a new Balwin Properties residential development, De Aanzicht in Atlantic Hills, Western Cape. The retaining wall acts as the buffer between the engineered platforms on the lower level and the protected nature conservation area to the east. 

 Creating an interface 

 Nigel Barr from KCE Consulting Engineers says: “The residential scheme of De Aanzicht nestles up against a large Renosterveld reserve. With slopes of up to 12m high, which included soft rock outcrop, creating a ‘soft’ interface required the use of an undulating retaining system, combining access, planting and stormwater management.” 

 Over time, the slope treatment will disappear behind planting, hiding the “under-the-skin” engineering of soft soil anchors, tied back foundations and the use of mixed-pattern Terraforce block facings. 

The design and engineered flexibility the Terraforce system provides was a huge plus, suiting the intricate nature and shapes of the terraced and undulating embankment.

 Special design to secure the embankment 

 KCE designed and detailed a two-part system to adequately secure the embankment, whilst taking great care to avoid encroachment into the environmental buffers and restricted no-go zones around the conservation area. 

 A series of soil-nailed terraces with the front faces stabilised with a gunnite shotcrete was created as the initial lateral support system for the embankment. A series of terraced Terraforce retaining structures was constructed in front, providing the aesthetics and landscape-friendly portions for the face of the embankment. The Terraforce walls act as a cladding while also providing planting pockets, accessible terraces and maintenance access routes throughout the embankment area. 

 Material choice for gravity solutions 

 Barr highlighted: “Terraforce is the ‘go-to’ block for almost all the gravity solutions throughout the region. The aesthetics appeal of the rock-face finish blocks suited the overall environment and blends into the surrounding landscape with ease. The blocks are both familiar, proven and readily available, making it the obvious choice.” 

Project details 

Client: Balwin Properties 

Architect: DHK Cape Town 

Civil and structural engineer: KCE Consulting Engineers 

Area: 1 620m² 

Installation by Terraforce-recommended contractor: Decorton Retaining Systems 

Blocks supplied by Terraforce-licenced manufacturer: Klapmuts Concrete 

For more information, contact Terraforce: 

Tel: +27 21 465 1907 

Email: info@terraforce.com  

Website: www.terraforce.com